Method of enhancing the compressive strength of hydraulic cement composition

ABSTRACT

The compressive strength of a hydrated hydraulic cement composition such as Portland cement concrete is enhanced by the addition of a very small amount of certain select synthetic non-ionic surface active agents to the compositions.

This is a continuation of application Ser. No. 860,037 filed Dec. 12, 1977, which is a division of application Ser. No. 744,465 filed Nov. 24, 1976, both abandoned.

BACKGROUND OF THE INVENTION

This invention relates to improved hydraulic cement compositions. More particularly, this invention pertains to cement compositions such as Portland cement concretes, mortars, etc., having significantly enhanced compressive strengths due to the incorporation therein of a relatively very small proportion of certain synthetic surface active agents.

Among the various materials added to hydraulic cement compositions such as Portland cement concretes are those which have been found able to affect the interaction between the water and the cement particles in the composition. For instance chemical additives have been used for some time which act to render the wet hydraulic mix more "plastic" at a given proportion of water to cement in the hydraulic mix, or conversely to allow less water to be used in the mix to obtain a given plasticity. These materials are referred to as "dispersing" agents in some cases or as "water reducing" agents in others, although in many instances both terms can be applied to the same additive material.

The ability of a chemical additive to reduce the amount of mix water required to obtain a given plasticity, or "slump" as it is referred to in the art, has led to the valuable utility of the material as a compressive strength-enhancing additive for hydraulic cements. It is well established that other factors being equal, a reduction in the amount of the water employed relative to the cement in the mix (the w/c ratio) will lead to an increase in the extended compressive strength of the hydrated cement compositions as usually measured after 28 days from the preparation of the cement mixture. Among the various chemical materials which have been employed as strength-enhancing, water-reducing agents are carbohydrates; such as saccharides and polysaccharides, for example, starch and derivatives thereof such as pregelatinized starch, dextrin, corn syrup, etc.; polyhydroxy polycarboxylic compounds such as tartaric acid and mucic acid; lignosulfonic acid and salts thereof, for example, sodium lignosulfonate; water soluble borates and silicones; etc., as well as mixtures of the foregoing. These substances are effective as water reducing, strength enhancing additives since they produce no side effects deleterious to strength, although many of these materials will also act to retard the setting time of the hydraulic cement mixture. These materials therefore are normally used in conjunction with a set accelerator such as calcium chloride or a formate salt to offset the retardation effect in instances where such retardation is not also a desired effect.

A chemical agent which has the ability to reduce surface tension in water might be expected to increase the plasticity of wet hydraulic cement mixes by entraining air in the wet mix and indeed the art has long recognized this utility of so-called surface active agents or surfactants. The increased air entrained during mixing due to the presence of the surfactant is normally retained in the final hydrated product, and thus another wide use for surface active materials in the hydraulic cement art has been as air-entraining agents for the hydrated cement product to render it more durable and resistant to freeze-thaw cycles. The amounts of air entrained for these purposes are however deleterious to the compressive strength of the final set product.

SUMMARY OF THE INVENTION

Through my experiments with various commercially available synthetic surface active agents, I have found that certain members of this large group are particularly effective by themselves as very low addition rate additives to increase the extended compressive strength of hydrated hydraulic cement compositons such as Portland cement concrete, etc. More particularly, I have found that certain synthetic organic compounds which are surface active, have only a low solubility in water, and further which exhibit a limited foaming ability will significantly enhance the extended or overall (28 day) compressive strength of the hydrated cement product at very low addition rates, i.e. when added in amounts of only about 0.001 to about 0.1% by weight based upon the cement. The surface-active additives I employ in my invention do not entrain air in the hydrated cement in amounts deleterious to compressive strength and thus are effective by themselves as strength-enhancing agents. One very desirable practical advantage offered by the use of my surfactant additives is that due to their low foamability and low water solubility, the danger of entraining unwanted high air contents in the cement product through an accidental overdose of the additive is considerably diminished.

As aforementioned, synthetic surface active agents have been employed previously as additives to hydraulic cement compositions. As far as I am aware, however, the art has not recognized that the surfactants of my invention can be added by themselves in very low amounts for the purpose of increasing the compressive strength of hydraulic cement compositions, particularly Portland cement concretes intended for structural uses.

DETAILED DESCRIPTION OF THE INVENTION INCLUDING THE PREFERRED EMBODIMENTS

The strength-enhancing synthetic additives of the invention are surface active (surfactants), that is, they reduce the surface tension of water or reduce interfacial tension between liquids or between a liquid and a solid. Further, the synthetic surfactant additives of my invention have only a low solubility in water as is evidenced by their having a limited cloud point value. The "cloud point" of surfactants is a term conventionally employed in the surfactant art. It is used to indicate the sudden onset of turbidity of surfactant solution on raising the temperature ("NON-IONIC SURFACTANTS", Schick, Vol. I, P 571 (1967)). As used herein, the term indicates the temperature in degrees centigrade at which a sudden onset of turbidity is observed in a 1% solution of the surfactant in water. I have found that this low solubility as indicated by cloud point is an important criterion in the ability of the surfactant to increase the compressive strength of hydraulic cements at low addition rates. Through my experiments with various synthetic surfactants, I have determined that useful surfactants according to my invention have cloud points which do not exceed about 80 degrees centigrade.

I have found further that surface activity and low water solubility are not the only important criteria in determining the usefulness of surfactants as low addition rate, strength-enhancing additives to hydraulic cements according to my invention. My experiments below with certain surfactants have further shown that they must also be low foam-producing, and I have found that this requisite low foaming property can be reliably assessed using a mechanically-induced, agitative foaming test developed by me.

In this test, the foaming ability of the surfactant is assessed by measuring the height of foam produced as the result of mechanical agitation at room temperature of a given amount of the surfactant dissolved or dispersed in a water-alcohol solution. The value obtained by the test procedure is termed herein and in the attached claims as the "mechanically-induced agitatedfoam height" of the surfactant.

This test procedure is best described in detail having reference to the accompanying drawings wherein;

FIG. 1 is a perspective view of the mechanical apparatus for controlled agitation of the surfactant sample, and;

FIG. 2 is a perspective view of the ruled container used in the apparatus in which the surfactant sample is deposited and ensuing foam height measured.

Referring now to FIG. 1, container 10 has mounted therein an electric speed reducer motor 11 (one seventy-fifth horsepower, 1800 rpm, 115 VAC) suitably wired through a capacitor 12 and linked to a gear reducer 13 (30/1 ratio output, 8.2 inch-pounds torque at 60 rpm). Both the motor and the gear reducer are products of the Bondine Electric Co., Chicago, Illinois. The speed reducer 13 is connected to a crank arm 14 which in turn is pivotally attached to rack 16 through a ballend 15. The rotational motion of crank arm 14 is thus converted to a reciprocating, somewhat longitudinal, motion of rack 16 through this arrangement. Rack 16 cooperates with pinion gear 17, which is secured to shaft 22. Support frame 19 rigidly anchors a pair of 3/4 inch journal bearings 18 to container 10. Shaft 22 is secured at one end to a housing 23 for the sample container, and then journaled through first bearing 18, a support 21 for rack 16, pinion gear 17, and at its opposite end through the second bearing 18. Rack 20 is free to pivot about shaft 22. Through this arrangment, the reciprocating motion of rack 20 is converted to an oscillatory motion of housing 23.

Housing 23 has a set screw 24 threaded through its upper end. The set screw is welded to a metal plate having a rubber pad 25 adhered to its surface. Rotation of screw 24 in turn raises or lowers the padded metal plate within the housing. Housing 23 has another rubber pad 30 at the bottom thereof.

The surfactant sample is held in a glass container shown in FIG. 2. Container 26 has four leak-proof glass sides and glass bottom 27. Ground glass top 28 is removable. A ruler 29 graduated in millimeters is taped to the outside of the container. The glass container is described in ASTM C115-73, section 2.2.4 It is rectangular as shown, having inside dimensions of 2 inches by 11/2 inches by 8 inches in height.

Operation of the device is as follows. The surfactant sample to be tested is placed in container 26. Top 28 is then positioned in a fluid-tight manner, e.g. by first wetting the edge of container 26 contacting the ground glass top 28. The sealed container is then placed in housing 23 and the set screw 24 tightened to hold the glass container. Activation of motor 11 turns crank arm 14, which in turn causes rack 16 to move within slide 20. Movement of the rack causes pinion gear 17 to rotate one way, then another, which in turn oscillates housing 23 holding container 26. The device is constructed such that housing 23 inverts 180 degrees about a horizontal axis through the center of the container 26, turning the container upside down and back again to its original upright position once each second of time.

"Mechanically-induced agitated foam height" is calculated herein in the following manner. A 0.10% by weight solution of the surfactant in a mixture containing 95% by weight distilled water and 5% by weight isopropyl alcohol (Fisher Scientific Co. Catalogue No. A-419, Certified A.C.S. Spectranalized 2-Propanol) is prepared. A ruler graduated in millimeters is affixed to the outside of the glass container such that the zero point of the ruler is exactly at the height of 100 milliliters of a liquid placed therein (measured at the meniscus of the liquid). 100 Milliliters of the aforementioned surfactant solution is pipetted into the container, and the container secured in the housing 23. The container is agitated for five minutes. After one minute has elapsed following cessation of the agitation, the height of the foam produced is measured. An "Individual Value" is recorded which is an average of the height across the entire surface of the foam produced. The sample is discarded and the entire procedure may be repeated one or more times, the final recorded value in the case of multiple readings being an "Average Foam Height", an actual numerical average of the Individual Values".

My experiments with the synthetic surfactants below have shown that in addition to surface-activity and low solubility as indicated by the limited cloud point value mentioned previously, useful synthetic low addition rate strength-enhancing cement additives according to the invention are those which in addition exhibit mechanically-induced agitated average foam height values of less than about 30 millimeters.

While both ionic and no-ionic surface active agents have been tested for strength enhancement in concrete in my experiments, the majority of my experimental work has been with synthetic surface active agents of the non-ionic type. Synthetic non-ionic surface active agents are well known in the art. They are characterized as exhibiting no ionic charge in aqueous solution. Hydrophilic character is often due to the presence of ether linkages, hydroxy groups, etc., in the molecule. All of the non-ionic surface active agents found useful for purposes of my invention are commercially available products.

Illustrative of the synthetic non-ionic low addition rate strength enhancing surfactants preferred for use in my invention are those members meeting the aforementioned low solubility and low foamability requirements and belonging to such classes as:

(a) Alkyl aryl polyether alcohols such as the condensation products of alkylphenols, e.g. octylphenol and nonylphenol, with alkylene oxides, e.g. ethylene oxide; exemplary members of this group found useful according to the invention include condensation products of octylphenol and nonylphenol having a particular degree of exthoxylation and offered commercially, for example, under the tradenames "Triton", "IGEPAL CO", and "Surfonic N";

(b) Block copolymers of alkylene glycols or alkylene diamines and one or more alkylene oxides, such as those prepared by the sequential addition of propylene oxide and then ethylene oxide to a propylene glycol nucleus, or by the sequential addition of ethylene oxide and then propylene oxide to an ethylene glycol base or to the diamine base; exemplary members of this group found useful according to this invention include certain block copolymers of propylene glycol, propylene oxide and ethylene oxide offered commercially under the tradenames "Pluronic", and "Pluronic R"; and "Tetronic".

(c) Acetylenic glycols and reaction products thereof with alkylene oxides such as ethylene oxide; exemplary members of this group found useful herein include tertiary acetylenic glycols offered commercially under the tradenames "Surfynol 104" and certain condensation product thereof prepared by reacting such with ethylene oxide and offered commercially under the tradenames "Surfynol 440" and "Surfynol 465".

The additives of my invention are effective as extended (28 day) compressive strength enhancing agents in only very small amounts. I have found significant strength enhancement after 28 days of the hydraulic cement compositions employing amounts in the range of only about 0.001 to about 0.1 percent by weight of the cement, preferably about 0.001 to about 0.05%.

The additives according to my invention are particularly valuable for increasing the extended compressive strength of Portland cement compositions, especially Portland cement concrete. Portland cement is by far the most widely used hydraulic cement. The term "hydraulic cement" as employed herein includes those inorganic cements which, when mixed with water, set and harden as a result of chemical reactions between the water and the compounds present in the cement. Organic "glues", pastes, etc., are not included within this definition. The term "Portland cements" as employed herein include those products prepared by heating a mixture of limestone and clay or shale, or other calcareous and argillaceous materials to a fused state. The fused product, which is called clinker, is interground with a few percent, normally about 4 to 6 percent, of a retarder such as gypsum.

The term "concrete" as used herein includes a mixture of such hydraulic cements and inert aggregates. Typical aggregates include conventional "coarse" aggregates such as gravel, granite, limestone, quartz sieve, etc., as well as those materials conventionally referred to as "fine" aggregates such as sand and fly ash. Conventional hydraulic cement concretes, e.g. Portland cement concretes, employ major amounts, i.e. over 50%, usually up to about 75% by volume of such aggregates in the set product.

The additives of the invention are especially suited for use in concretes intended for structural uses where high compressive strengths are particularly sought. These concrete compositions employ water to cement ratios of less than 1, usually from about 0.4 to about 0.6, and when hardened have compressive strength values typically in excess of 2000 psi after 28 days of preparation.

The compositions of the invention can include conventional additional optional additives such as set accelerators, etc., but do not include materials which deleteriously affect the extended strengths such as strength-diminishing amounts of petroleum or other hydrocarbon oils, air-entraining agents, etc.

The term "consisting essentially of " as employed herein and in the claims to define the compositions of the invention is intended as inclusive of those ingredients specifically mentioned herein as well as any additional unspecified conventional ingredients, but is intended to be exclusive of additional unspecified ingredients in amounts which deleteriously affect the extended or overall compressive strength of the set compositions.

In my experiments described below, Portland cements from various manufacturers were employed to make hydratable compositions. The cements all met ASTM standards for Portland cements. Where employed, the concrete compositions were prepared according to ASTM C494 test procedures. Determinations of the amount of air entrained in the hydrated samples produced in the experiments below were made according to ASTM test procedure No. C231. Also, the "slump" of the wet mixes produced in the experiments was determined according to ASTM test procedure No. C143. This is a measure of the relative consistency or plasticity of the wet mix. The compressive strength of the mixes given below was determined by preparing test specimens and curing in accordance with ASTM procedure No. C192. The compressive strengths of the specimens were measured after 1, 7 and 28 days in accordance with ASTM C39.

The Examples below are representative of the results I have obtained from a number of actual experiments testing the effect of the specific surfactants listed on Portland cement compositions. They are intended as illustrative only of my invention.

EXAMPLE I

This example illustrates the effect of small amounts of various commercially produced synthetic non-ionic polyol surfactants sold commercially by the WYANDOTTE CHEMICALS CORP. under the trademark "Pluronic", upon the air content and compressive strength of Portland cement concretes. As aforementioned, the concretes in this and later Examples, were prepared in accordance with ASTM procedures, and measurements of the water to cement ratio, slump, air content and compressive strengths of the hydrated concretes made in each case were also made using ASTM procedures. For comparison, a "blank" containing no additive was identically prepared and tested. As will be understood by one skilled in the art, measurements are first made with respect to the "blank" composition. The compositions containing the surfactant additives are then prepared and sufficient water added to the mix to give a "slump" as close as possible to that exhibited by the blank, plus or minus about 1/2 inch. The amount of water actually used is recorded for calculation of the W/C ratio, and subsequently air content and compressive strengths at 1, 7 and 28 days are measured.

The "Pluronic" polyols employed herein have been fully described in the literature. They are 100% active, non-ionic block copolymers made by controlled addition of the propylene oxide to the two hydroxyl groups of a propylene glycol nucleus. The resulting hydrophobe can be tailored to any desired length, varying from 800 to several thousands in molecular weight. The customized addition of ethylene oxide to this hydrophobe "sandwiches" it between hydrophilic poly (oxyethylene) groups of controlled length constituting from 10 to 80% of the final molecule. The nomenclature of the "Pluronic" materials employed herein is that of the manufacturer.

The "Pluronic R" surfactants employed herein are similar to the aforedescribed "Pluronic" materials. They are also non-ionic block copolymers, but the copolymer structure is reversed. They are prepared by the sequential addition of ethylene oxide and then propylene oxide to an ethylene glycol base. The copolymer again contains a hydrophobic polyoxypropylene portion and a hydrophilic polyoxyethylene portion. Specific details concerning the chemical nature of the "Pluronic" and "Pluronic R" materials are given in Table I below, and the aforementioned effects of such on Portland cement concretes are shown in Tables II-IX. In these and all the Tables following, the manufacturer and the ASTM type of the cement used is given. Also, the percentage addition rate for the additive shown in the Tables is that as calculated based on the weight of the cement solids (solids on solids).

                  TABLE I                                                          ______________________________________                                                  Typical                                                               "Pluronic"                                                                              Molecular        % Poly (oxyethylene)                                 Product  Wt. of Poly (oxy-                                                                               Hydrophilic Unit in                                  Designation                                                                             propylene) Hydrophobe                                                                           total Molecule                                       ______________________________________                                         L31       950             10                                                   L35       950             50                                                   L42      1200             20                                                   L43      1200             30                                                   L44      1200             40                                                   L61      1750             10                                                   L62      1750             20                                                   L63      1750             30                                                   L72      2050             20                                                   L81      2250             10                                                   P84      2250             40                                                   L92      2750             20                                                   L101     3250             10                                                   P103     3250             30                                                   P104     3250             40                                                   P105     3250             50                                                   F108     3250             80                                                   L121     4000             10                                                   L122     4000             20                                                   P123     4000             30                                                   F127     4000             70                                                   25R1     2500             10                                                   31R1     3100             10                                                   25R2     2500             20                                                   31R2     3100             20                                                   25R4     2500             40                                                   31R4     3100             40                                                   25R8     2500             80                                                   ______________________________________                                    

                  TABLE II                                                         ______________________________________                                         PLURONIC            COMPRESSIVE                                                Polyol              STRENGTH PSI                                               (0.02%)  W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                              ______________________________________                                         CANADA I CEMENT BATCH A                                                        Blank    0.59   33/4    1.9   1023  3175  4130                                 L-81     0.58   33/4    2.2   1230  3537  4524                                 L-92     0.56   3       2.6   1321  3684  4627                                 L-62     0.56   31/4    2.5   1484  3959  4799                                 L-63     0.55   3       2.8   1428  3684  4695                                 P-103    0.48   4       7.2   1421  3418  4190                                 CANADA I CEMENT BATCH B                                                        Blank    0.60   43/4    2.0   1098  3247  4468                                 P-105    0.48   5       8.8   1046  2646  3410                                 ______________________________________                                    

                  TABLE III                                                        ______________________________________                                         PLURONIC            COMPRESSIVE                                                Polyol              STRENGTH-PSI                                               (0.05%)  W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                              ______________________________________                                         ATLANTIC I CEMENT BATCH C                                                      Blank    0.60   41/2    1.4   1098  2909  3907                                 L-81     0.57   41/4    1.9   1261  3207  4504                                 L-92     0.51   33/4    4.0   1572  3645  4803                                 L-62     0.55   4       2.7   1361  3426  4397                                 L-63     0.55   41/4    2.9   1337  3346  4592                                 L-44     0.55   4       3.6   1293  3318  4345                                 L-35     0.55   41/4    4.0   1234  3116  4218                                 P-103    0.46   6       12.7   875  2053  2566                                 F-127    0.45   51/4    13.8   764  1600  2033                                 F-108    0.46   51/4    13.0   772  1986  2324                                 ______________________________________                                    

                  TABLE IV                                                         ______________________________________                                         PLURONIC            COMPRESSIVE                                                Polyol              STRENGTH-PSI                                               (0.05%)  W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                              ______________________________________                                         ATLANTIC I CEMENT BATCH D                                                      Blank    0.60   41/2    1.4   1297  2753  4146                                 L-62     0.57   41/2    2.5   1329  3131  4309                                 L-63     0.57   41/2    2.8   1289  3048  4381                                 L-44     0.56   5       3.4   1421  3227  4361                                 P-84     0.46   51/4    10.1  1373  2646  3969                                 L-35     0.56   41/2    3.1   1397  3203  4261                                 P-104    0.44   61/4    14.7   557  1202  1556                                 P-103    0.44   41/4    9.6   1393  2785  3493                                 P-123    0.48   43/4    9.0   1313  2646  3322                                 ______________________________________                                    

                  TABLE V                                                          ______________________________________                                         PLURONIC            COMPRESSIVE                                                 R                  STRENGTH-PSI                                               Polyols  W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                              ______________________________________                                         ATLANTIC I CEMENT BATCH E                                                      Blank    0.61   33/4    1.6   1011  2976  4425                                 0.05% 31 R1                                                                             0.57   31/2    2.5   1114  3697  4818                                 0.05% 31 R2                                                                             0.57   4       2.7   1051  3478  4683                                 0.05% 25 R1                                                                             0.57   4       2.6   1067  3486  4783                                 0.05% 25 R2                                                                             0.57   31/2    2.5   1166  3796  4990                                 0.05% 25 R8                                                                             0.57   31/2    2.8   1043  3549  4846                                 0.05% 31 R4                                                                             0.56   3       2.9   1126  3462  4970                                 0.05% 31 R4                                                                             0.57   41/2    3.3   1015  3418  4747                                 0.05% 25 R4                                                                             0.57   41/4    3.2    999  3438  4679                                 CANADA I CEMENT BATCH E'                                                       Blank    0.60   43/4    1.6   1130  2264  4329                                 Blank    0.59   33/4    1.9    859  1934  3497                                 0.01% 25 R1                                                                             0.57   33/4    2.2   1289  2519  4616                                 0.01% 25 R2                                                                             0.57   33/4    2.3   1381  2586  4616                                 UNIVERSAL ATLAS INDIANA I CEMENT BATCH E"                                      Blank    0.60   4        1.4   784  3358  5181                                 0.01% 35 R1                                                                             0.58   31/2    2.3    879  3633  5368                                 0.01% 35 R2                                                                             0.58   33/4    2.1    875  3848  5376                                 0.01% 31 R4                                                                             0.57   3       2.4   1011  3935  5805                                 ______________________________________                                    

                  TABLE VI                                                         ______________________________________                                                             COMPRESSIVE                                                PLURONIC            STRENGTH-PSI                                               L92      W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                              ______________________________________                                         ATLANTIC I CEMENT BATCH F                                                      Blank    0.60   43/4    1.4   1162  2745  4150                                 0.001%   0.58   41/4    2.2   1186  3000  4281                                 0.005%   0.56   41/4    2.6   1452  3410  4584                                 0.010%   0.56   31/2    2.6   1444  3394  4639                                 0.010%   0.56   51/4    2.7   1170  3076  4301                                 0.025%   0.54   41/4    3.2   1249  3199  4675                                 0.050%   0.52   5       5.5   1448  3159  4126                                 0.100%   0.49   61/4    8.9   1281  2773  3768                                 ______________________________________                                    

                  TABLE VII                                                        ______________________________________                                                             COMPRESSIVE                                                PLURONIC            STRENGTH-PSI                                               Polyol   W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                              ______________________________________                                         CANADA I CEMENT BATCH G                                                        Blank    0.60   31/2    1.8   1154  3183  4389                                 0.02% L-121                                                                             0.58   41/4    1.9   1257  3557  4652                                 0.04% L-121                                                                             0.58   3       1.9   1277  3772  4735                                 0.02% L-101                                                                             0.58   4       1.9   1297  3597  4540                                 0.04% L-101                                                                             0.58   3       1.7   1289  3529  4719                                 0.02% L-81                                                                              0.57   31/2    2.0   1110  3454  4532                                 0.04% L-81                                                                              0.58   33/4    1.8   1226  3700  4687                                 0.02% L-61                                                                              0.57   31/4    2.1   1134  3482  4472                                 0.04% L-61                                                                              0.57   41/4    2.0   1353  3617  4974                                 CANADA I CEMENT BATCH H                                                        Blank    0.60   4       1.6   1158  3243  4544                                 0.01% L-122                                                                             0.57   31/2    2.3   1337  3549  4651                                 0.02% L-122                                                                             0.57   5       3.8   1297  3493  4548                                 0.04% L-122                                                                             0.57   41/2    3.1   1421  3688  4743                                 0.01% L-92                                                                              0.57   43/4    2.6   1309  3577  4787                                 0.02% L-92                                                                              0.55   31/2    3.1   1417  3800  4918                                 0.04% L-92                                                                              0.51   4       5.3   1345  3490  4417                                 ______________________________________                                    

                  TABLE VIII                                                       ______________________________________                                                             COMPRESSIVE                                                PLURONIC            STRENGTH-PSI                                               Polyol   W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                              ______________________________________                                         IDEAL I CEMENT BATCH I                                                         Blank    0.59   41/2    1.4   1122  3275  5073                                 0.04% L92                                                                               0.56   41/4    1.8   1273  3553  5595                                 0.04% L92                                                                               0.57   33/4    1.9   1202  3760  5734                                 0.08% L92                                                                               0.56   31/2    2.0   1241  3649  5730                                 ATLANTIC I CEMENT BATCH J                                                      Blank    0.60   41/2    1.3   1170  3227  4795                                 0.05% L92                                                                               0.57   33/4    2.2   1281  3601  5344                                 ATLANTIC I CEMENT BATCH K                                                      Blank    0.60   4       1.3   1114  3418  4942                                 0.001% L92                                                                              0.58   41/2    1.8   1289  3728  5005                                 0.005% L92                                                                              0.56   31/2    2.1   1472  3716  5181                                 0.010% L92                                                                              0.57   41/2    1.9   1345  3720  5097                                 0.050% L92                                                                              0.56   43/4    2.2   1389  4039  5387                                 0.100% L92                                                                              0.55   33/4    2.1   1421  4162  5527                                 CANADA I CEMENT BATCH L                                                        Blank    0.59   41/4    2.3   908   2905  3907                                 0.10% L92                                                                               0.52   5       5.8   1146  3092  3935                                 IDEAL I CEMENT BATCH M                                                         Blank    0.57   41/4    1.5   1214  3744  5368                                 0.005% L92                                                                              0.55   41/2    2.3   1202  3923  5547                                 0.010% L92                                                                              0.54   33/4    2.3   1174  4074  5630                                 0.050% L92                                                                              0.55   41/4    2.1   1162  4007  5718                                 0.10% L92                                                                               0.55   41/4    2.0   1162  4230  5809                                 UNIVERSAL ATLAS INDIANA I CEMENT BATCH N                                       Blank    0.58   41/4    1.3   863   3398  5025                                 0.005% L92                                                                              0.56   31/2    2.3   991   3947  5447                                 0.010% L92                                                                              0.55   31/2    2.2   1027  3772  5403                                 0.050% L92                                                                              0.55   31/4    2.3   991   3780  5395                                 0.100% L92                                                                              0.55   4       2.1   895   3573  5145                                 ATLANTIC I CEMENT* BATCH O                                                     Blank    0.60   41/4    1.2   1074  3052  4480                                 0.005% L92                                                                              0.56   4       2.1   1301  3490  5196                                 0.010% L92                                                                              0.56   41/4    2.3   1373  3525  5145                                 0.050% L92                                                                              0.55   4       2.4   1381  3669  5204                                 IDEAL I CEMENT BATCH P                                                         Blank    0.57   4       1.6   1086  3279  5033                                 0.0025% L92                                                                             0.55   4       2.0   1261  3971  5447                                 0.005% L92                                                                              0.54   31/2    2.2   1265  4043  5686                                 0.010% L92                                                                              0.55   41/4    2.5   1321  3939  5797                                 ______________________________________                                          *Different Lot from Batch J and K.                                       

                  TABLE IX                                                         ______________________________________                                                             COMPRESSIVE                                                PLURONIC            STRENGTH-PSI 28 -                                          Polyol   W/C    Slump   % Air 1 Day 7 Days                                                                               28 DAYS                              ______________________________________                                         ATLANTIC I CEMENT BATCH Q                                                      Blank    0.61   33/4    1.5    840  3068  4699                                 0.02% L31                                                                               0.57   3       2.8   1035  3454  5372                                 0.02% L62                                                                               0.56   21/2    2.9   1050  3537  5244                                 CANADA I CEMENT BATCH R                                                        Blank    0.59   31/2    1.9   1170  3326  4337                                 0.02% L72                                                                               0.56   31/4    2.3   1428  3812  4799                                 0.02% L92                                                                               0.54   3       3.4   1432  3915  4727                                 0.02% L43                                                                               0.56   21/2    2.6   1281  3577  4504                                 CANADA I CEMENT BATCH S                                                        Blank    0.61   41/4    1.4   1110  3271  4409                                 0.01% L92                                                                               0.57   41/2    2.2   1245  3796  4986                                 0.01% L42                                                                               0.58   31/2    2.1   1281  3486  4747                                 0.01% L62                                                                               0.57   4       2.0   1329  3609  4651                                 0.01% L72                                                                               0.58   41/2    2.0   1192  3458  4528                                 0.01% L122                                                                              0.57   41/2    2.2   1285  3812  4440                                 0.005% L122                                                                             0.58   4       1.9   1230  3438  4532                                 CANADA I CEMENT BATCH T                                                        Blank    0.60   33/4    1.6   1134  3350  4417                                 0.02% L61                                                                               0.58   31/2    1.8   1361  3593  4803                                 0.02% L62                                                                               0.57   33/4    2.1   1452  3752  4767                                 0.02% L63                                                                               0.57   31/4    2.1   1333  3525  4755                                 0.02% L43                                                                               0.57   31/2    2.3   1202  3358  4512                                 0.02% L42                                                                               0.57   31/2    2.3   1241  3346  4452                                 0.02% L31                                                                               0.58   41/2    2.2   1142  3386  4257                                 ______________________________________                                    

The total data I have gathered from all of my experiments with the "Pluronic" polyol additives has led me to exclude the Pluronic block copolymers "P-84"; "P-103"; "P-104"; "P-105"; "F-108"; "P-123"; and "F-127" as low addition rate strength-enhancing additives for hydraulic cement compositions. These materials, I have found, when added in an amount within the range of 0.001 to about 0.1 tend to cause relatively large amounts of incremental air to be entrained in the hydrated cement compositions and have no, or a negative effect on compressive strength development. My preferred block copolymer additives according to the invention are those designated Pluronic "L-62"; "L-72"; and "L-92"; since I have found that these gave optimum compressive strength increase most consistently. The useful "Pluronic" type block copolymer additives, that is, those prepared by adding propylene oxide to propylene glycol, followed by the addition of ethylene oxide as additives according to my invention appear to be those wherein (A) the typical molecular weight of the poly(oxypropylene) hydrophobe is from about 950 to about 1750 and the % poly (oxyethylene) in the total molecule is from about 10 to about 50; or (B) wherein such molecular weight is from about 1750 to about 2750 and such % poly (oxyethylene) is from about 10 to about 30; or (C) wherein such molecular weight is from about 2750 to about 4000 and such % poly (oxyethylene) is from about 10 to about 20. Mixtures of such copolymers selected from such groups (A), (B), and (C) can also obviously be employed herein. The preferred such "Pluronic" type additives would appear to be those wherein the typical molecular weight of poly(oxyethylene) hydrophobe ranges from about 1450 to about 3000, and further wherein the % poly (oxyethylene) in the total molecule ranges between about 15 and about 35.

Further representative experimental data on the effects of such preferred "Pluronic" block copolymers as additives according to the invention are illustrated in Table X below.

                  TABLE X                                                          ______________________________________                                                             COMPRESSIVE                                                PLURONIC            STRENGTH - PSI                                             Polyol   W/C    Slump   % Air                                                                               1 Day  7 Days                                                                               28 Days                              ______________________________________                                         UNIVERSAL ATLAS INDIANA I CEMENT BATCH U                                       Blank    0.60   33/4    1.5   871   3748  5324                                 0.02% L62                                                                               0.56   31/4    2.9   887   3740  5328                                 0.02% L52                                                                               0.57   5       3.0   987   3999  5571                                 0.02% L72                                                                               0.57   31/2    2.4   931   4074  5563                                 0.02% L92                                                                               0.56   4       2.7   859   3680  5742                                 UNIVERSAL ATLAS INDIANA I CEMENT BATCH V                                       Blank    0.60   4       1.4   744   3474  5356                                 0.02% L62                                                                               0.57   23/4    2.7   883   3983  5837                                 0.02% L72                                                                               0.57   33/4    2.8   816   3864  5471                                 UNIVERSAL ATLAS INDIANA I CEMENT BATCH W                                       Blank    0.60   33/4    1.4   788   3545  5097 -0.02% L62 0.57 33/4 3.0 91                                               9 3784 5527                          0.02% L72                                                                               0.5    41/2    2.5   883   3724  5571                                 0.02% L92                                                                               0.57   33/4    2.9   891   3716  5423                                 ATLANTIC I CEMENT BATCH X                                                      Blank    0.60   4       1.4   1074  3529  4902                                 0.02% L62                                                                               0.56   3       2.6   1237  4003  4998                                 0.02% L72                                                                               0.57   33/4    2.4   1090  3704  4964                                 0.02% L92                                                                               0.57   41/4    2.8   1039  3796  5073                                 CANADA I CEMENT BATCH Y                                                        Blank    0.60   41/4    1.6   1015  3123  4361                                 0.02% L62                                                                               0.58   41/4    2.7   1166  3561  4739                                 0.02% L72                                                                               0.57   31/2    2.4   1281  3700  4830                                 0.02% L72                                                                               0.58   33/4    2.7   1158  3374  4568                                 0.02% L92                                                                               0.57   41/2    3.3   1150  3677  4476                                 0.01 L92 0.57   51/4    2.4   1054  3167  3987                                 0.005% L92                                                                              0.58   43/4    2.0   1054  3235  4285                                 0.02% L42                                                                               0.58   43/4    2.5   1226  3700  4345                                 ______________________________________                                    

All of the "Pluronic R" type polyol block copolymers I have tested have been found useful as additives according to my invention. These include materials wherein the typical molecular weight of the poly (oxypropylene) hydrophobe was about 2500 and % poly (oxyethylene) units was in the range of about 10 to 80, and materials wherein the such typical molecular weight was about 31 and such % poly (oxyethylene) was about 10-40.

Table XI below lists each of the polyol block copolymers shown in Table I with its corresponding "cloud point", "surface tension", and "mechanically-induced, agitated foam height" values as previously described. In Table XI, the "Number of Tests" associated with the "Average Foam Height" is the actual number of tests performed on each sample, the individual values of which were averaged in accordance with the procedure described above.

                  TABLE XI                                                         ______________________________________                                                                      Mechanically-                                                                  Induced, Agitated                                          Cloud   Surface     Foam Height                                       PLURONIC Point   Tension     No. of                                                                               Average foam                                Polyol   (C°)                                                                            (Dynes/cm)  Tests Height (mm)                                 ______________________________________                                         P-104    81      38.5        2     62                                          P-105    91      40.8        2     83                                          F-108    >100    45.5        2     124                                         P-123    90      34.3        2     57                                          F-127    >100    41.8        2     >150                                        P-103    86      37.6        2     47                                          P-84     74      44.9        2     32                                          L-63     34      45.9        2     24                                          L-122    19      33.7        2     27                                          L-42     37      49.5        4     8                                           25 R4    40      42.6        3     10                                          25 R8    80      50.8        2     7                                           31 R4    31      44.4        2     18                                          L-43     42      50.3        2     7                                           L-72     25      42.9        2     11                                          L-62     32      45.3        2     16                                          L-92     26      37.8        2     15                                          L-61     24      43.5        2     6                                           L-101    15      34.9        2     5                                           25 R1    28      41.0        2     10                                          31 R1    25      36.6        2     6                                           L-81     20      43.7        2     4                                           L-121    14      32.5        2     6                                           31 R2    30      41.2        2     11                                          L-35     77      53.0        2     5                                           L-44     65      48.3        2     8                                           L-31     37      50.4        2     8                                           25 R2    33      40.1        2     9                                           ______________________________________                                    

All of the "Pluronic" polyols listed in Table XI are "surface active", in this case that is, are able to reduce the surface tension of water. None of the listed materials exhibited a surface tension as a 0.01% aqueous solution at 25° C. above about 55 dynes per centimeter. The "Pluronic" types "P-103"; "P-104"; "P-105"; "F-108"; "F-123" and "F-127" all were excessively soluble for use according to my invention, exhibiting a cloud point in excess of about 80° C. These also exhibited high foaming ability as evidenced by their having a mechanically-induced, agitated foam height value in excess of about 30 millimeters. The polyol "P-84" had a solubility near the 80° C. limit, but was too high a foam producer, showing a foam height in excess of about 30 millimeters according to my test procedure. The preferred "Pluronic" types "L-62"; "L- 92"; and "L-72" exhibited cloud points in the range of about 20° to 35° C., and mechanically-induced, agitated foam heights in the range of about 10 to 20 millimeters.

EXAMPLE II

In this example, the efficacy of certain synthetic surface active alkyl aryl polyether alcohols as low addition rate, compressive strength-enhancing additives for hydraulic cement compositions is illustrated. In particular, representative results of the effects of certain non-ionic surface active condensation products of octylphenol or nonylphenol with ethylene oxide offered under the commercial names "Triton X" (Rohm & Haas CO), "Igepal Co" (General Aniline & Film Corp), and "Surfonic N" (Jefferson Chemical Co., Inc), upon Portland cement concretes at low addition rates are presented herein.

The "TritonX" non-ionic materials employed herein are well known, commercially available surfactants. They are prepared by condensing octylphenol with a varying number of moles of ethylene oxide. The "Surfonic N" and "Igepal Co" surfactants utilized herein are similarly well known commercially available non-ionic surfactants prepared by condensing nonylphenol with a varying number of moles of ethylene oxide. Hydrophilic character is given to the alkylphenol hydrophobic moiety by the incorporation of the poly (oxyethylene) units. The particular alkyl aryl polyether alcohols mentioned in the experiments of this Example are listed in Table XII below, along with detailed chemical and physical information relevant to my invention and described previously. The representative effect of the addition of these materials on Portland cement concrete air, strength etc. is illustrated in the following Tables XIII-XX. Tests and measurements were performed and taken as in Example I.

                                      TABLE XII                                    __________________________________________________________________________                                 Mechanically-induced                                                          Agitated Foam Height                                Alkyl Aryl                                                                             % Poly(oxy-                                                                            Cloud                                                                              Surface    Average                                         Polyether                                                                              ethylene) in                                                                           PT. Tension                                                                               No. Foam                                            Alcohol Total Molecule                                                                         (°C.)                                                                       (Dynes/cm)                                                                            Tests                                                                              Height (mm)                                     __________________________________________________________________________     Triton X-100                                                                          66-68    65  31     2   >150                                            Triton X-114                                                                          60-63    25  30     2   129                                             Triton X-45                                                                           51       >0  29     2   31                                              Triton X-35                                                                           39       >0  29     2   2                                               Triton X-15                                                                           18       >0  Insol  1   0                                               Surfonic N-95                                                                         64-67    54.2                                                                               30.5   2   >150                                            Surfonic N-60                                                                         54       Insol                                                                              28.9   2   62                                              Surfonic N-40                                                                         44       Insol                                                                              28 (Approx.)                                                                          2   5                                               Surfonic N-20                                                                         29       Insol                                                                              Insol  1   0                                               Surfonic N-10                                                                         17       Insol                                                                              Insol  1   0                                               Igepal CO-530                                                                         54       Insol                                                                              28 (Approx.)                                                                          2   45                                              Igepal CO-520                                                                         50       Insol                                                                              30     2   37                                              Igepal CO-430                                                                         44       Insol                                                                              Insol  2   14                                              __________________________________________________________________________

                                      TABLE XII                                    __________________________________________________________________________      ATLANTIC I CEMENT BATCH A                                                     Alkyl Aryl                                                                     Polyether             COMPRESSIVE STRENGTH - PSI                               Alcohol    W/C                                                                               Slump                                                                              % Air                                                                              1 Day 7 Days                                                                               28 Days                                      __________________________________________________________________________     Blank      0.59                                                                              4   1.3 1440  3664  5586                                         0.002% Triton X-35                                                                        0.57                                                                              33/4                                                                               2.1 1798  4488  6028                                         UNIVERSAL ATLAS INDIANA I CEMENT BATCH B                                       Blank      0.58                                                                              41/4                                                                               1.1 1062  3366  5113                                         0.002% Triton X-35                                                                        0.55                                                                              41/4                                                                               2.1 1281  3865  5650                                         CANADA I CEMET BATCH C                                                         Blank      0.59                                                                              41/4                                                                               1.5 1158  3291  4369                                         0.002% Triton X-35                                                                        0.57                                                                              4   2.2 1154  3402  4480                                         CANADA I CEMENT BATCH D                                                        Blank      0.55                                                                              41/2                                                                               1.4 1444  3398  4389                                         Blank      0.56                                                                              4   1.9 1214  3064  4114                                         0.004% Triton X-35                                                                        0.56                                                                              4   2.0 1532  3816  4795                                         0.010% Triton X-35                                                                        0.54                                                                              41/4                                                                               2.0 1456  3478  4528                                         ATLANTIC I CEMENT BATCH E                                                      Blank      0.61                                                                              4   1.4 955   3016  4651                                         0.006% Triton X-15                                                                        0.58                                                                              33/4                                                                               2.2 891   3565  5045                                         0.006% Triton X-35                                                                        0.58                                                                              33/4                                                                               2.1 1011  3856  5196                                         0.006% Triton X-45                                                                        0.57                                                                              31/2                                                                               2.2 1046  3700  5300                                         0.006% Triton X-114                                                                       0.56                                                                              31/2                                                                               2.7 1023  3497  5173                                         0.006% Triton X-100                                                                       0.58                                                                              41/2                                                                               3.0 959   3497  4922                                         0.006% Triton X-100                                                                       0.57                                                                              31/2                                                                               2.5 951   3609  5244                                         __________________________________________________________________________

                                      TABLE XIV                                    __________________________________________________________________________     ATLANTIC I CEMENT BATCH F                                                      Alkyl Aryl                                                                     Polyether             COMPRESSIVE STRENGTH - PSI                               Alcohol    W/C                                                                               Slump                                                                              % Air                                                                              1 Day 7 Days                                                                               28 Days                                      __________________________________________________________________________     Blank      0.61                                                                              4   1.4 951   3283  4914                                         0.010% Triton X-15                                                                        0.59                                                                              4   2.0 959   3446  4994                                         0.010% Triton X-35                                                                        0.58                                                                              31/2                                                                               2.0 991   3462  5216                                         0.010% Triton X-45                                                                        0.57                                                                              31/2                                                                               2.4 1134  3891  5419                                         0.010% Triton X-114                                                                       0.56                                                                              33/4                                                                               3.3 1146  3748  5491                                         0.010% Triton X-100                                                                       0.54                                                                              31/2                                                                               4.0 1094  3673  5017                                         ATLANTIC I CEMENT BATCH G                                                      Blank      0.61                                                                              41/4                                                                               1.5 824   2964  4544                                         0.02% Triton X-15                                                                         0.58                                                                              41/4                                                                               2.1 979   3501  5153                                         0.02% Triton X-35                                                                         0.57                                                                              4   2.3 1074  3772  5427                                         0.02% Triton X-45                                                                         0.55                                                                              4   3.6 1214  3875  5364                                         0.02% Triton X-114                                                                        0.50                                                                              4   7.0 1043  3410  4588                                         0.02% Triton X-100                                                                        0.49                                                                              41/2                                                                               8.0 935   3108  4086                                         ATLANTIC I CEMENT BATCH H                                                      Blank      0.58                                                                              31/2                                                                               1.5 1432  4072  5295                                         0.05% X-114                                                                               0.46                                                                              71/4                                                                               14.0                                                                                760  1990  2485                                         __________________________________________________________________________

                  TABLE XV                                                         ______________________________________                                         ATLANTIC I CEMENT BATCH H                                                      Alkyl Aryl                                                                     Polyether          COMPRESSIVE                                                 Alcohol            STRENGTH - PSI                                              Triton X-35                                                                            W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                               ______________________________________                                         Blank   0.61   4       1.6   911   3080  4608                                  0.001%  0.58   41/4    2.4   1011  3529  5200                                  0.001%  0.57   31/2    2.0   923   3617  5085                                  0.002%  0.59   4       2.1   971   3299  4942                                  0.004%  0.58   4       2.1   979   3517  4994                                  0.008%  0.58   41/4    2.1   1023  3728  5272                                  0.016%  0.58   33/4    2.2   1074  3744  5447                                  0.032%  0.57   41/4    2.5   919   3649  5117                                  ATLANTIC I CEMENT BATCH I                                                                                         3 days                                      ______________________________________                                         Blank   0.60   43/4    1.6   895   1906  4627                                  0.01%   0.58   43/4    2.1   975   2196  5033                                  0.05%   0.58   5       2.3   907   2101  4846                                  0.10%   0.58   51/4    2.2   931   2053  4695                                  ______________________________________                                    

                  TABLE XVI                                                        ______________________________________                                          ATLANTIC I CEMENT BATCH J                                                     Alkyl Aryl                                                                     Polyether          COMPRESSIVE                                                 Alcohol            STRENGTH - PSI                                              Triton X-45                                                                            W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                               ______________________________________                                         Blank   0.61   33/4    1.6    848  3346  4791                                  0.001%  0.58   33/4    2.6    995  3712  5276                                  0.004%  0.58   31/4    2.2   1007  3370  5232                                  0.004%  0.59   41/4    2.2   1062  3756  5431                                  0.008%  0.57   31/2    2.4    995  3728  5296                                  0.016%  0.56   41/2    3.7   1043  3720  4934                                  0.016%  0.55   31/2    3.3   1058  3923  5300                                  CANADA I CEMENT BATCH K                                                                       1st.   2nd*                                                     ______________________________________                                         Blank   0.59   4           1.8 1031  2921  4385                                0.001%  0.58   51/4        1.9 1114  3231  4592                                0.001%  0.57   31/2        2.0 1210  3533  4870                                0.004%  0.58   31/4        2.0 1114  3430  4803                                0.008%  0.56   51/2        2.5 1202  3525  4834                                0.008%  0.55   41/2        2.5 1273  3617  5025                                0.025%  0.52   51/2   31/2 3.4 1305  3720  4950                                0.025%  0.53   41/2   31/2 3.9 1162  3271  4389                                0.05%   0.53   23/4   21/4 3.7 1110  2909  4122                                0.10%   0.51   41/4   33/4 6.9  987  2582  3621                                0.10%   0.53   51/2   51/2 7.5 --    --    --                                  ______________________________________                                          Observer's Notes:                                                              *Higher addition rates such as 0.025 and 0.05 show a severe loss of slump      in the first five minutes after discharge from mixer.                          The incremental air is proportional to the addition rate.                      The effect of W/C on compressive strength is very critical at the higher       addition rates such as 0.025%.                                           

                  TABLE XVII                                                       ______________________________________                                         CANADA I CEMENT BATCH A                                                        Alkyl Aryl                                                                     Polyether                                                                      Alcohol            COMPRESSIVE                                                 Igepal             STRENGTH - PSI                                              CO-430  W/C    Slump   % Air 1 Day 3 Days                                                                               28 Days                               ______________________________________                                         Blank   0.59   33/4    1.9    859  1934  3497                                  Blank   0.60   43/4    1.6   1130  2264  4329                                  0.005%  0.57   31/4    2.1   1353  2706  4472                                  0.010%  0.57   31/4    2.3   1357  2678  4707                                  CANADA I CEMENT BATCH B                                                                                           7 Days                                      Blank   0.58   41/4    1.7   1249  3239  4405                                  0.005%  0.57   43/4    2.1   1417  3541  4906                                  0.010%  0.56   41/2    2.5   1508  3812  4699                                  CANADA I CEMENT BATCH C                                                        Blank   0.59   31/4    1.7   1233  3430  4679                                  0.005%  0.57   31/2    2.2   1385  3565  4771                                  0.010%  0.56   4       2.5   1361  3736  4902                                  UNIVERSAL ATLAS INDIANA I CEMENT BATCH D                                       Blank   0.60   41/2    1.4   796   3458  5188                                  0.0025% 0.57   31/2    2.0   955   3935  5610                                  0.005%  0.57   4       2.1   931   3899  5750                                  0.01%   0.57   4       2.7   979   3931  5459                                  UNIVERSAL ATLAS INDIANA I CEMENT BATCH E                                       Blank   0.61   33/4    1.3   852   3386  5328                                  0.0025% 0.58   31/2    2.1   991   3828  5761                                  0.005%  0.58   31/2    2.2   983   3903  5642                                  0.005%  0.59   41/2    2.2   947   3752  5483                                  UNIVERSAL ATLAS INDIANA I CEMENT BATCH F                                       Blank   0.60   33/4    1.4   788   3545  5097                                  0.005%  0.58   31/2    2.3   856   3645  5352                                  ______________________________________                                    

                  TABLE XVIII                                                      ______________________________________                                         ATLANTIC I CEMENT BATCH G                                                      Alkyl Aryl                                                                     Polyether                                                                      Alcohol            COMPRESSIVE                                                 Igepal             STRENGTH - PSI                                              CO-430  W/C    Slump   % Air 1 Day 7 Days 38 Days                              ______________________________________                                         Blank   0.60   4       1.5    963  3271   4647                                 0.002%  0.57   31/2    2.0   1198  3585   4938                                 0.004%  0.57   33/4    2.0   1301  3617   5208                                 0.008%  0.56   31/2    2.3   1460  4031   5626                                 ATLANTIC I CEMENT BATCH H                                                      Blank   0.60   41/4    1.4   1027  3529  4978                                  0.002%  0.60   41/4    2.2   1194  3891  5224                                  0.004%  0.58   33/4    2.1   1138  3891  5077                                  0.008%  0.58   5       2.4   1078  3780  5181                                  0.02%   0.55   33/4    3.4   1154  3696  5352                                  ATLANTIC I CEMENT BATCH I                                                      Blank   0.60   4       1.4   1074  3529  4902                                  0.008%  0.57   33/4    2.2   1234  3840  5077                                  ATLANTIC I CEMENT BATCH J                                                      Blank   0.60   5       1.4    863  3183  4623                                  Blank   0.59   31/2    1.4   1086  3788  5248                                  0.004%  0.58   31/2    2.1   1086  3629  5181                                  0.008%  0.57   31/2    2.4   1118  3665  5177                                  ATLANTIC I CEMENT BATCH K                                                      Blank   0.60   4       1.5    987  3338  4620                                  0.008%  0.57   3       2.5   1198  3852  5125                                  0.008%  0.58   33/4    2.3   1241  3792  4994                                  0.02%   0.56   31/4    3.6   1206  3684  4850                                  0.02%   0.57   33/4    3.5   1046  3573  4930                                  0.04%   0.58   23/4    3.9    857  3119  4206                                  ______________________________________                                    

                  TABLE XIX                                                        ______________________________________                                         ATLANTIC I CEMENT BATCH L                                                      Alkyl Aryl                                                                     Polyether               COMPRESSIVE                                            Alcohol          %      STRENGTH - PSI                                         Igepal    W/C    Slump   Air  1 Day 7 Days                                                                               28 Days                              ______________________________________                                         Blank     0.60   31/2    1.6   999  3493  4942                                 0.02% CO-430                                                                             0.55   31/2    3.3  1313  3927  5451                                 0.02% CO-520                                                                             0.53   31/2    4.8  1472  4222  5535                                 0.02% CO-530                                                                             0.52   41/4    6.0  1325  3856  4914                                 ATLANTIC I CEMENT BATCH M                                                      Blank     0.58   4       1.3  1176  3933  5104                                 0.05% CO-520                                                                             0.52   43/4    6.0  1241  3482  4454                                 0.05% CO-530                                                                             0.50   51/4    8.0  1136  3234  3905                                 ______________________________________                                    

                  TABLE XX                                                         ______________________________________                                         ATLANTIC I CEMENT BATCH A                                                      Alkyl Aryl                                                                     Polyester              COMPRESSIVE                                             Alcohol                STRENGTH - PSI                                          Surfonic                                                                               W/C    Slump   % Air 1 Day 3 Days                                                                               28 Days                               ______________________________________                                         Blank   0.61   41/4    1.5    896  1966  4548                                  0.02% N-10                                                                             0.58   43/4    2.8   1031  2252  5117                                  0.02% N-20                                                                             0.59   43/4    2.0   1150  2316  5324                                  0.02% N-40                                                                             0.57   43/4    2.4   1086  2495  5407                                  0.02% N-60                                                                             0.54   51/4    5.3   1257  2543  5316                                  0.02% N-95                                                                             0.51   51/4    6.5   1062  2200  4556                                  ______________________________________                                         ATLANTIC I CEMENT BATCH B                                                                                          7 Days                                     ______________________________________                                         Blank   0.60   31/2    1.6    999  3493  4942                                  0.02% N-40                                                                             0.56   3       2.6    979  3549  5041                                  0.02% N-60                                                                             0.52   51/2    6.4   1174  3350  5352                                  0.02% N-60                                                                             0.50   23/4    5.4   1313  3935  5065                                  ______________________________________                                         ATLANTIC I CEMENT BATCH C                                                      Blank   0.60   31/4    1.5   1074  3501  4699                                  0.02% N-40                                                                             0.58   3       2.8   1225  3840  4950                                  0.02% N-60                                                                             0.54   51/4    6.5   1289  3422  4484                                  ______________________________________                                    

My experimental work with the "Tritons" leads me to exclude "Triton X-100", "Triton X-114" and "Triton X-45" as low addition rate, strength enhancing additives according to my invention. These higher ethoxylated condensates of octylphenol entrain considerable amounts of air at the higher addition levels within my 0.001 to 0.10 addition rate. This high air entrainment as aforementioned is detrimental to strength enhancement. "Triton X-45" although a marginal performer, is excluded from my invention since my experiments show it has a tendency to entrain air at the higher addition rate within the aforementioned range, although this tendency did not appear to be as great as in the cases of the higher ethoxylated "Triton X-100" and "Triton X-114".

My experimental work with the ethoxylated nonylphenols "Surfonics" and "Igepals" would appear to correspond to my findings with respect to the ethoxylated octylphenols, the "Tritons". Again I found that as the addition rate increased within the 0.001 to 0.10 range, the materials having a percent ethoxylation over about 50, "Surfonic N-60", "Surfonic N-95", "Igepal CO-530" and "Igepal CO-520", showed a tendency to entrain incremental air. As emphasized previously, this tendency is detrimental to compressive strength gain, and can even be so deleterious to strength as to be dangerous, for example should the material be "overdosed" by the concrete preparer.

An examination of the data in Table XII shows all of the polyether condensates of the Example which I employ as low addition rate strength enhancers according to my invention ("Triton X-35"; "X-15"; "Surfonic N-10"; "N-20", "N-40"; and "Igepal CO-430") to be either insoluble, or to have a "cloud point" near zero. While the remaining polyethers excluded from my invention had cloud points beneath the 80° C. maximum, all exhibited excessive foaming properties as indicated by the "mechanically-induced agitated foam heights" of greater than about 30 millimeters, the maximum according to my invention. As expected, "Triton X-45" was marginal in this respect.

The preferred alkyl aryl polyether alcohol condensates according to my invention are "Triton X-35", "Surfonic N-40" and "Igepal CO-430" which contained about 35 to about 50 percent poly (oxyethylene) in the molecule.

EXAMPLE III

In this Example, the effect of the addition of certain synthetic surface active acetylinic glycols and ethoxylated products thereof as low addition rate, compressive strength enhancing materials according to the invention is illustrated. In particular, representative results of the effects of certain synthetic acetylinic glycols and ethoxylated products thereof offered commercially under the name "Surfynol" by Airco Chemicals and Plastics upon Portland cement concrete compositions at low addition rates are presented herein.

The particular "Surfynol" products used herein are listed in Table XXI along with physical and chemical information relevant to the present information. "Surfynol 104" is a non-ionic surface active agent composed of 2,4,7,9-tetramethyl-5 decyn-4,7 diol. It is a tertiary acetylinic glycol. "Surfynol 440" is a non-ionic surface active agent, and is prepared by reacting "Surfynol 104" with alkylene oxide, i.e. ethylene oxide in a mole ratio of 3.5 moles of ethylene oxide per mole of the tetramethyl decyndiol. "Surfynol 465" is also a non-ionic surface active agent prepared by reacting "Surfynol 104" with ethylene oxide, the mole ratio being 10 moles of ethylene oxide per mole of the tetramethyl decyndiol. The concrete test results performed as in the foregoing Examples are given Table XXII.

                                      TABLE XXI                                    __________________________________________________________________________                       Cloud                                                                               Surface                                                 Acetylinic                                                                            % Poly(oxyethylene)                                                                       Point                                                                               Tension                                                                               Mechanically-Induced Agitated Foam Height        Glycol In total Molecule                                                                         (°C.)                                                                        (Dynes/cm)                                                                            No. Tests                                                                              Average Foam Height                      __________________________________________________________________________                                           (mm)                                     Surfynol 104                                                                          0          Insoluble                                                                           45.1   1       0                                        Surfynol 440                                                                          41         Insoluble                                                                           44.0   1       0                                        Surfynol 465                                                                          66         61   44.5   2       21                                       __________________________________________________________________________

                  TABLE XXII                                                       ______________________________________                                         ATLANTIC I CEMENT BATCH A                                                      Acetylinic             COMPRESSIVE                                             Glycol                 STRENGTH - PSI                                          "Surfynol"                                                                             W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                               ______________________________________                                         Blank   0.60   4       1.5    963  3271  4647                                  0.005% 440                                                                             0.57   33/4    2.3   1146  3549  4950                                  0.005% 465                                                                             0.56   31/4    2.3   1325  3939  5240                                  0.005% 104                                                                             0.57   31/2    2.0   1210  3637  5173                                  ______________________________________                                         CANADA I CEMENT BATCH B                                                                                            3 Days                                     ______________________________________                                         Blank   0.60   43/4    1.6   1130  2264  4329                                  Blank   0.59   33/4    1.9    859  1934  3491                                  0.01% 440                                                                              0.57   3       2.6   1210  2574  4635                                  0.01% 465                                                                              0.57   4       2.8   1186  2395  4365                                  ______________________________________                                         UNIVERSAL ATLAS INDIANA I CEMENT BATCH C                                                                          7 Days                                      ______________________________________                                         Blank   0.60   41/2    1.4   796   3458  5188                                  0.01 465                                                                               0.56   31/2    2.7   871   3947  5395                                  0.02% 465                                                                              0.55   3       2.9    859  3899  5248                                  ______________________________________                                         IDEAL I CEMENT BATCH D                                                         Blank   0.58   31/2    1.6    871  3382  4781                                  0.01% 465                                                                              0.56   33/4    2.9   921   3429  5091                                  0.05% 465                                                                              0.56   31/2    2.4   940   3284  5208                                  0.10% 465                                                                              0.57   4       2.3   948   3476  5082                                  ______________________________________                                    

All of the "Surfynol" products tested in Table XXII were effective as low addition rate, compressive strength enhancing additives according to my invention. Again, all of the effective materials were surface-active as evidenced by the fact that each lowered the surface tension of water, were either "insoluble" or had a solubility below the 80° C. approximate limit, and were low foamers as evidenced by the low mechanically-induced agitated foam height values.

EXAMPLE IV

In this Example, the efficacy of a proprietary commercial synthetic non-ionic surfactant "Plurafac RA-20" offered commercially by the Wyandotte Chemicals Corp. as a low addition rate, compressive strength-enhancing agent according to the invention is illustrated. The "Plurafac" products are described as 100% active, non-ionic biodegradable surfactants of straight chain, primary aliphatic, oxyethylated alcohols. Physical and chemical information pertinent to this invention concerning "Plurafac RA-20" as well as results representative of the performance of the surfactant as a low addition rate, strength enhancing additive as in the foregoing Examples, are presented in Table XXIII.

                                      TABLE XXIII                                  __________________________________________________________________________               % Poly (oxy                                                                            Cloud                                                                              Surface                                                                               Mechanically-Induced -ethylene)                                                in Point Tension  agitated Foam Height (mm)       Additive  Total Molecule                                                                         (°C.)                                                                       (Dynes/cm)                                                                            No. Tests                                                                           Average Foam Height                          __________________________________________________________________________     Plurafac RA = 20                                                                         not available                                                                          45  32.9   2    87                                           __________________________________________________________________________     ATLANTIC L CEMENT BATCH A                                                                                   COMPRESSIVE                                       PLURAFAC                     STRENGTH - PSI                                    RA-20     W/C     Slump                                                                              % Air   1 Day                                                                               7 Days                                                                              28 Days                                __________________________________________________________________________     Blank     0.58    31/2                                                                               1.5     1432 4072 5295                                   0.01%     0.55    4   3.1     1292 4117 5309                                   0.025%    0.51    5   7.0     1358 3651 4496                                   0.05%     0.48    41/2                                                                               8.8     1381 3618 433                                    __________________________________________________________________________

My results testing the effect of "Plurafac RA-20" as a low addition rate, compressive strength-enhancing additive according to the invention indicate that as the amount of this surfactant is increased in my addition range, very high strength-damaging incremental air is entrained. The surfactant additive lowered the surface tension of water and had a low solubility, but created an amount of foam, 87 millimeters, in excess of the approximate 30 millimeter limit according to my invention.

EXAMPLE V

This Example illustrates the usefulness of small amounts of synthetic block copolymer non-ionic surfactants offered commercially under the name "Tetronic" by the Wyandotte Chemicals Corporation as additives according to the invention. These materials are block copolymers prepared in a manner similar to the "Pluronic" block copolymers of Example I, except that ethylene diamine is used as the base to which ethylene oxide and propylene oxide are added sequentially. As in the case of the "Pluronics", the products vary depending upon the amount poly (oxypropylene) hydrophobe and the % poly (oxyethylene) hydrophilic units present in the molecule. The "Tetronic" block copolymers empolyed herein are listed in Table XXIV, and the physical and chemical properties thereof relevant to this invention in Table XXV. Tables XXVI and XXVII represent the test results in concrete performed as in previous Examples.

                  TABLE XXIV                                                       ______________________________________                                                 Typical                                                                "Tetronic"                                                                             Molecular        % Poly (oxyethylene)                                  Product wt. of poly (oxy Hydrophilic Unit                                      Designation                                                                            propylene) Hydrophobe                                                                           in Total Molecule                                     ______________________________________                                         1502    6501-7000        20                                                    1102    4501-5000        20                                                    702     2501-3000        20                                                    1501    6501-7000        10                                                    1301    5501-6000        10                                                    1101    4501-5000        10                                                    901     3501-4000        10                                                    701     2501-3000        10                                                    ______________________________________                                    

                  TABLE XXV                                                        ______________________________________                                                                Mechanically-Induced                                    Cloud       Surface    Agitated Foam Height                                    "Tetronic"                                                                             Point   Tension             Av. Foam                                   Designation                                                                            (°C.)                                                                           (Dynes/cm) No. of Tests                                                                            Ht. (mm)                                   ______________________________________                                         1502    70      35 (estimated)                                                                            2        44                                         1102    31      36 (estimated)                                                                            2        29                                         702     27      41.1       3        5                                          1501    15      35.1       2        3                                          1301    16      34.7       3        9                                          1101    17      35.7       1        0                                          901     20      37.3       1        0                                          701     22      40.9       1        0                                          ______________________________________                                    

                  TABLE XXVI                                                       ______________________________________                                         CANADA I CEMENT BATCH A                                                                           COMPRESSIVE                                                 "Tetronic"         STRENGTH - PSI                                              Polyol  W/C    Slump   % Air 1 Day 7 Days                                                                               28 Days                               ______________________________________                                         Blank   0.60   41/2    1.5   1082  3250  4110                                  0.01%  901                                                                             0.58   51/4    2.1   1210  3438  4687                                  0.01% 1101                                                                             0.58   31/2    2.0   1261  3525  4154                                  0.01% 1301                                                                             0.58   31/2    2.0   1154  3342  4417                                  0.01% 1501                                                                             0.58   41/4    1.9   1122  3330  4369                                  0.01% 1102                                                                             0.57   53/4    3.1   1078  3414  4230                                  0.01% 1102                                                                             0.55   43/4    2.9   1142  3390  4405                                  0.01% 1502                                                                             0.58   4       1.9   1074  3430  4381                                  ______________________________________                                         CANADA I CEMENT BATCH B                                                        Blank   0.60   5       1.5   1214  3501  4803*                                 0.02%  701                                                                             0.59   4       1.8   1146  3219  4440                                  0.02% 1101                                                                             0.59   4       1.6   1409  3414  4504                                  0.02% 1301                                                                             0.58   41/2    2.0   1234  3450  4616                                  0.02% 1501                                                                             0.59   41/2    1.7   1202  3458  4584                                  0.02%  702                                                                             0.57   31/3    2.2   1253  3513  4810                                  0.02% 1102                                                                             0.57   63/4    4.9   1110  3255  4238                                  0.02% 1502                                                                             0.58   33/4    1.9   1222  3583  4830                                  ______________________________________                                          *Experimenter's Note:                                                          Unusually high compressive strength value for a blank of this brand and        type of cement. Results of experiment questionable.                      

                  TABLE XXVII                                                      ______________________________________                                         ATLANTIC I CEMENT BATCH C                                                                         COMPRESSIVE                                                 Tetronic           STRENGTH - PSI                                              Polyol  W/C    Slump   % Air 1 Day    7 Days                                   ______________________________________                                         Blank   0.59   4       1.6    986     3388                                     0.05%  701                                                                             0.58   41/2    1.7   1097     3514                                     0.05%  901                                                                             0.57   41/2    1.8   1210     3855                                     0.05% 1101                                                                             0.57   33/4    1.7   1137     3611                                     0.05% 1301                                                                             0.56   31/2    2.4   1168     3761                                     0.05% 1501                                                                             0.57   33/4    1.7   1160     3725                                     0.05%  702                                                                             0.57   33/4    2.2   1055     3389                                     0.05% 1102                                                                             0.51   5       7.5   1099     3185                                     0.05% 1502                                                                             0.52   33/4    5.8   1162     3266                                     ______________________________________                                         ATLANTIC I CEMENT BATCH D                                                      0.05%  702                                                                             0.56   31/2    2.4   No cylinders Cast                                 0.05% 1102                                                                             0.53   53/4    7.2   No cylinders Cast                                 0.05% 1502                                                                             0.53   33/4    6.0   No cylinders Cast                                 ______________________________________                                    

My experiments with the "Tetronic" type block copolymers listed in Tables XXIV and XXV lead me to exclude those designated as "1102" and "1502". As the addition rate was increased to 0.05%, these additives showed a tendency to entrain large amounts of incremental air, which as my previous experiments have shown, usually offsets any strength gain, or even results in a net loss of strength as compared to the blank at 28 days.

EXAMPLE VI

In this Example, representative results are given of only preliminary evaluations I have made of commercially available synthetic surfactants in addition to those of Examples I-V as low addition rate, strength-enhancing additives for hydraulic cement compositions.

The results of an experiment involving the addition of small amounts of certain non-ionic, surface active polyethylene glycol esters offered commercially under the name "ARMAK KESSCO PEG " by Armour Industrial Chemical Co. are given in Table XXVIII. The materials shown are polyoxyethylene esters of oleic acid. The number following the "PEG" in the Table indicates the molecular weight of the polyoxyethylene glycol portion of the molecule.

                  TABLE XXVIII                                                     ______________________________________                                         ATLANTIC I CEMENT BATCH                                                        Polyethylene            COMPRESSIVE                                            Glycol Ester     %      STRENGTH - PSI                                         (Di-oleate)                                                                              W/C    Slump   Air  1 Day 7 Days                                                                               28 Days                              ______________________________________                                         Blank     0.59   33/4    1.4  1154  3406  4926                                 0.001 PEG 200                                                                            0.57   33/4    1.7  1305  3752  5073                                 0.01  PEG 200                                                                            0.56   4       2.0  1313  3796  4814                                 0.001 PEG 400                                                                            0.57   41/4    2.2  1325  3708  5065                                 0.01  PEG 400                                                                            0.56   41/4    2.9  1206  3478  4655                                 0.001 PEG 600                                                                            0.57   33/4    1.9  1373  3907  5244                                 0.01  PEG 600                                                                            0.55   4       2.8  1245  3597  4759                                 0.05  PEG 400                                                                            0.58   21/2    2.7  1070  3115  4643                                 ______________________________________                                    

Other commercially available surface active products that I have also tested as low addition rate strength-enhancing additives for Portland cement concrete in the manner of the previous Examples included (a) "BRIJ 92" (Atlas Chemical Industries, Inc.) a none-ionic polyoxythylene ether of oleyl alcohol which when added at 0.02% exhibited increase in compressive strength of the concrete; "BRIJ 30" (Atlas Chemical Industries, Inc.) a non-ionic polyoxyethylene ether of lauryl alcohol which at the 0.02% addition level tended to entrain a high amount of incremental air which discouraged further testing, and "BRIJ 72" (Atlas Chemical Industries, Inc.) a non-ionic polyoxyethylene ether of stearyl alcohol which when added at the 0.02% level exhibited the same tendencies as "BRIJ 30"; (b) "SPAN 80" (Atlas ChemicalIndustries, Inc.) a non-ionic fatty acid partial ester of sorbitol anhydride (sorbitan monooleate) which when added at a level of 0.02% caused high incremental air entrainment and low compressive strength; (c) "TWEEN 81" (Atlas Chemical Industries, Inc.) a non-ionic polyoxyethylene derivative of a fatty acid partial ester of sorbitol anhydride (polyoxyethylene 5 sorbitanmonooleate), which, at a 0.02% addition level entrained a moderate amount of incremental air and exhibited a slightly lower compressive strength than the blank; (d) "TERGITOL 15-S-3" (Union Carbide Corp.) a non-ionic polyethylene glycol ether of a linear alcohol which when added at a 0.02% addition level entrained a low amount of incremental air and exhibited a compressive strength increase; "TERGITOL 15-S-5" (Union Carbide Corp.) a non-ionic polyethylene glycol ether of a linear alcohol having a higher degree of ethoxylation than "TERGITOL 15-S-3" which when added at a level of 0.02% entrained a moderately high amount of incremental air and exhibited a slight compressive strength increase; "TERGITOL 15-S-7", a non-ionic polyethylene glycol ether of a linear alcohol having a higher degree of ethoxylation than "TERGITOL 15-S-3" and 15-S-5" and which at a 0.02% additive rate entrained a high amount of incremental air and exhibited a low compressive strength; (e) "TRITON H-66" (Rohm & Haas Co.) an anionic phosphate ester of an ethoxylated alkylphenol, potassium salt, which at a low addition level entrained high amount of incremental air and exhibited low compressive strength; (f) "TRITON H-55" (Rohm & Haas Co.) an anionic phosphate ester of an ethoxylated alkylphenol, potassium salt, which at a low addition level entrained no incremental air and exhibited a compressive strength increase, and (g) "GAFAC RM-410" (General Aniline & Film Corporation) an anionic free acid of a complex organic phosphate ester which at an addition rate of 0.05% entrained a moderate amount of incremental air and exhibited a low compressive strength; and (h) "ZONYL" (DuPont) fluorosurfactants, which included "ZONYL FSP", "FSN", "FSB", anionic, nonionic and anphoteric surfactants, all of which exhibited a tendency to entrain incremental air at low addition rates.

EXAMPLE VII

This example illustrates one practical application for the low addition rate, strength enhancing additives of my invention.

As aforementioned, the additives of my invention can be added by themselves to increase compressive strength, particularly extended or overall compressive strength of hydraulic cement mixes such as Portland cement concretes. In practice however, commercial admixtures for Portland cement compositions such as concrete are often designed to affect more than one property of the cement composition and thus are often compositions containing more than one ingredient, designed for example to alter the rate of hydration and the plasticity of the wet mix, the rate of hydration and the compressive strength, etc.

Thus the surfactant additives of my invention may be combined with e.g. compounds known to accelerate the set of hydraulic cement compositions. Representative of such set-accelerating materials are calcium chloride or other soluble chloride salt and non-chloride type accelerators such as formate salts, e.g. calcium formate and amine formates. In such a combination admixture the set accelerator comprises the major proportion, i.e. greater than 50% of the total additive compositions.

For additional compressive enhancement, the additive compositions can further include, in an amount for instance of from about 1 to about 25% of the total additive, conventional materials employed for this purpose. Representative of such materials are water-soluble, water-reducing carbohydrates such as monosaccharides, for example, glucose and fructose; disaccharides, for example, lactose and sucrose; trisaccharides, for example, raffinose; polysaccharides, for example, starch and cellulose, as well as derivatives thereof such as pre-gelatinized starch, dextrin, corn syrup and carboxymethylcellulose; polyhydroxy polycarboxylic compounds such as tartaric acid and mucic acid; lignosulfonic acid and salts thereof such as calcium, magnesium, ammonium and sodium lignosulfonate; water-soluble salts of boric acid, such as the alkali metal salts thereof; and water-soluble silicone compounds; as well as mixtures thereof. The aforementioned water-reducing agents may also have some retarding effect on the rate of hydration which normally is offset by the presence of the set accelerator component.

Since my low addition rate, compressive strength enhancing surfactant additives have low water-solubility as indicated by low cloud points, I prefer to include a small amount of a solubility-enhancing surfactant such as "Triton X-100" described above, to assist in solubilizing the surfactant additive of the invention. Such solubilizing action is most helpful in preventing the normally low-solubility strength-increasing surfactant additive of the invention from separating out as a visible separate phase, for instance as ambient temperatures surrounding the product increase.

The following is a detailed Example of a set-accelerating, strength-enhancing additive composition employing a preferred strength-enhancing surfactant of the invention, "Pluronic L-92" described above.

    ______________________________________                                                       % by Weight                                                      ______________________________________                                         Calcium chloride                                                                               84.8                                                           "Pluronic L-92" 1.94                                                           "Triton X-100"  0.83                                                           "Corn Syrup"    12.43                                                                          100.00                                                         ______________________________________                                    

A typical addition rate of this additive composition to structural Portland cement concretes lies generally in the range of from about 0.10 to about 2%, preferably about 0.3 to about 1% by weight of additive solids based upon cement solids. 

It is claimed:
 1. A hydraulic cement composition consisting essentially of a hydraulic cement and a synthetic surface active agent having the following characteristics: (a) a cloud point not in excess of about 80 degrees centigrade; and (b) a mechanically-induced agitated foam height of less than about 30 millimeters; said surface active agent being present in an amount within the range of from about 0.001 to about 0.10 percent by weight based upon said cement, said amount being sufficient to increase the compressive strength of the hydrated cement composition, said surface active agent further being selected from the group consisting of non-ionic block copolymers of alkylene diamines and one or more alkylene oxides; non-ionic acetylenic glycols and reaction products thereof with alkylene oxides; non-ionic polyethylene glycol esters; non-ionic polyoxyethylene ethers of oleyl alcohol; anionic phosphate esters of an ethoxylated alkylphenol, potassium salt; non-ionic block copolymers prepared by the sequential addition of ethylene oxide and then propylene oxide to an ethylene glycol base; non-ionic block copolymers prepared by sequential addition of propylene oxide and then ethylene oxide to a propylene glycol nucleus wherein (a) the molecular weight of the resulting poly (oxypropylene) portion of the copolymer ranges from about 1750 to about 2750 and the resulting percent poly(oxyethylene) portion in the total copolymer molecule is from about 10 to about 30 (b) said molecular weight is from about 2750 to about 4000 and said percent poly (oxyethylene) is from about 10 to about 20, (c) said molecular weight is 950 and said percent poly (oxyethylene) is 10, (d) said molecular weight is 1200 and said percent poly(oxyethylene) is 20; and mixtures of such.
 2. The composition of claim 1 wherein said cement is Portland cement.
 3. The composition of claim 1 wherein said cement is a structural concrete composition possessing a compressive strength as measured after 28 days of hydration in excess of 2000 p.s.i.
 4. The composition of claim 1 wherein said surface active agent exhibits a surface tension as a 0.01% aqueous solution at 25° C. of less than about 55 dynes per centimeter.
 5. The composition of claim 1 wherein said surface active agent is non-ionic, and is present in an amount of from about 0.001 to about 0.05%.
 6. The composition of claim 5 wherein said surface active agent possesses said cloud point in the range of about 20° to 35° C. and a said foam height in the range of about 10 to 20 millimeters.
 7. The composition of claim 5 wherein said surface active agent is prepared by adding ethylene oxide followed by propylene oxide to ethylene glycol and (a) the molecular weight of the resulting poly (oxypropylene) portion is about 2500 and the resulting percent poly (oxyethylene) units in the total copolymer molecule is in the range of about 10 to 80, or (b) said molecular weight of the said poly (oxypropylene) portion is about 3100 and said poly (oxyethylene) units is about 10 to
 40. 8. The composition of claim 1 wherein said surface active agent is a non-ionic acetylinic glycol or an alkoxylated product thereof.
 9. The composition of claim 8 wherein said surface active agent is a tertiary acetylinic glycol.
 10. The composition of claim 9 wherein said glycol is 2,4,7,9-tetramethyl-5 decyn-4,7 diol.
 11. The composition of claim 10 wherein said surface active agent is a reaction product of ethylene oxide and said acetylinic glycol.
 12. The composition of claim 11 wherein said product contains 3.5 to 10 moles of ethylene oxide per mole of acetylinic glycol.
 13. The composition of claim 1 wherein said surface active agent is a block copolymer of ethylene diamine, ethylene oxide and propylene oxide.
 14. The composition of claim 13 wherein the molecular weight of the resulting poly (oxypropylene) portion of said copolymer ranges from about 2500 to about 4500 and the resulting percent poly (oxyethylene) units in the total polymer molecule-ranges between about 10 to about
 20. 15. A Portland cement structural concrete composition consisting essentially of Portland cement, a major amount of aggregate, and from about 0.001 to about 0.1 percent by weight of said cement of a synthetic surface active agent having the following characteristics: (a) a cloud point not in excess of about 80 degrees centigrade; and (b) a mechanically-induced agitated foam height of less than about 30 millimeters; said composition when mixed with water being hydrated to a compressive strength in excess of 2000 p.s.i. after 28 days, said amount of surface active agent being sufficient to increase the compressive strength of said composition as compared to said composition having no such surface active agent, said surface active agent further being selected from the group consisting of non-ionic block copolymers of alkylene diamines and one or more alkylene oxides; non-ionic acetylinic glycols and reaction products thereof with alkylene oxides; non-ionic polyethylene glycols esters; non-ionic polyoxyethylene ethers of oleyl alcohol; anionic phosphate esters of an ethoxylated alkylphenol, potassium salt; non-ionic block copolymers prepared by the sequential addition of ethylene oxide and then propylene oxide to an ethylene glycol base; non-ionic block copolymers prepared by sequential addition of propylene oxide and then ethylene oxide to a propylene glycol nucleus wherein (a) the molecular weight of the resulting poly (oxypropylene) portion of the copolymer ranges from about 1750 to about 2750 and the resulting percent poly (oxyethylene) portion in the total copolymer molecule is from about 10 to about 30, (b) said molecular weight is from about 2750 to about 4000 and said percent poly (oxyethylene) is from about 10 to about 20, (c) said molecular weight is 950 and said percent poly (oxyethylene) is 10, (d) said molecular weight is 1200 and said percent poly (oxyethylene) is 20; and mixtures of such.
 16. The composition of claim 15 to which is added water sufficient to give a water to cement ratio of from about 0.4 to 0.6.
 17. A Portland cement composition consisting essentially of Portland cement and a synthetic surface active agent having the following characteristics; (a) a cloud point not in excess of about 80 degrees centigrade; and (b) a mechanically-induced agitated foam height of less than about 30 millimeters; said surface active agent being present in an amount within the range of from about 0.001 to about 0.10 percent by weight based upon said cement, said amount being sufficient to increase the compressive strength of the hydrated cement composition, said surfactant being a non-ionic block copolymer surfactant prepared by adding propylene oxide followed by ethylene oxide to propylene glycol wherein (a) the molecular weight of the resulting poly (oxypropylene) portion of the copolymer ranges from about 1750 to about 2750 and the resulting percent poly (oxyethylene) portion in the total copolymer molecule is from about 10 to about 30, (b) said molecular weight is from about 2750 to about 4000 and said percent poly (oxyethylene) is from about 10 to about 20, (c) said molecular weight is 950 and said percent poly (oxyethylene) is 10, (d) said molecular weight is 1200 and said percent poly (oxyethylene) is 20; and mixtures of such.
 18. A set-accelerating, compressive strength-enhancing additive composition for hydraulic cement composition, said additive composition consisting essentially of a major amount of set-accelerating agent for said cement and a small amount of a synthetic surface active agent having the following characteristics; (a) a cloud point not exceeding about 80 degrees centigrade; and (b) a mechanically-induced agitated foam height of less than about 30 millimeters, said amount of said surface active agent being within a range of about 0.001 to about 0.10 percent by weight of the cement in the said cement composition to which said additive composition is added and being sufficient to increase the compressive strength of said cement composition, said surface active agent further being selected from the group consisting of non-ionic block copolymers of alkylene diamines and one or more alkylene oxides; non-ionic acetylenic glycols and reaction products thereof with alkylene oxides; non-ionic polyethylene glycol esters; non-ionic polyoxyethylene ethers of oleyl alcohol; anionic phosphate esters of an ethoxylated alkylphenol, potassium salt; non-ionic block copolymers prepared by the sequential addition of ethylene oxide and then propylene oxide to an ethylene glycol base; non-ionic block copolymers prepared by sequential addition of propylene oxide and then ethylene oxide to a propylene glycol nucleus wherein (a) the molecular weight of the resulting poly (oxypropylene) portion of the copolymer ranges from about 1750 to about 2750 and the resulting percent poly (oxyethylene) portion in the total copolymer molecule is from about 10 to about 30, (b) said molecular weight is from about 2750 to about 4000 and said percent poly (oxyethylene) is from about 10 to about 20, (c) said molecular weight is 950 and said percent poly (oxyethylene) is 10, (d) said molecular weight is 1200 and said percent poly (oxyethylene) is 20; and mixtures of such.
 19. The composition of claim 18 wherein said set accelerating agent is calcium chloride.
 20. The composition of claim 18 wherein said surface active agent exhibits a surface tension as a 0.01% aqueous solution at 25° C. of less than about 55 dynes per centimeter.
 21. The composition of claim 18 wherein said surface active agent is present in an amount of from about 0.001 to about 0.05%.
 22. The composition of claim 26 wherein said surface active agent is prepared by adding ethylene oxide followed by propylene oxide to ethylene glycol and (a) the molecular weight of the resulting poly (oxypropylene) portion is about 2500 and the resulting percent poly (oxyethylene) units in the total copolymer molecule is in the range of about 10 to about 80, or (b) said molecular weight of the said poly (oxypropylene) portion is about 3100 and said poly (oxyethylene) units is about 10 to about
 40. 23. The composition of claim 18 wherein said surface active agent is a non-ionic acetylinic glycol or an alkoxylated product thereof.
 24. The composition of claim 23 wherein said surface active agent is a tertiary acetylinic glycol.
 25. The composition of claim 24 wherein said glycol is 2,4,7,9-tetramethyl-5 decyn-4,7 diol.
 26. The composition of claim 23 wherein said surface active agent is a reaction product of ethylene oxide and said acetylinic glycol.
 27. The composition of claim 26 wherein said product contains 3.5 to 10 moles of ethylene oxide per mole of acetylinic glycol.
 28. The composition of claim 18 wherein said surface active agent is a block copolymer of ethylene diamine, ethylene oxide and propylene oxide.
 29. The composition of claim 28 wherein the molecular weight of the poly (oxypropylene) portion of said copolymer ranges from about 2500 to about 4500 and the percent poly (oxyethylene) units in the total polymer molecule ranges between about 10 to about
 20. 30. A set-accelerating, compressive strength-enhancing additive composition for hydraulic cement composition, said additive composition consisting essentially of (a) a major amount of set-accelerating agent for said cement; (b) a water-soluble, water-reducing agent selected from the group consisting of carbohydrates; polyhydroxy polycarboxylic compounds; lignosulfonic acid and salts thereof; boric acid salts; silicone compounds; and mixtures thereof; and (c) a small amount of a synthetic surface active agent having the following characteristics; (1 ) a cloud point not exceeding about 80 degrees centigrade; and (2) a mechanically-induced agitated foam height of less than about 30 millimeters, said amount of surface active agent being within a range of about 0.001 to about 0.10 percent by weight of the cement in said cement composition to which said additive composition is added and being sufficient to increase the compressive strength of said cement composition, said surface active agent further being selected from the group consisting of non-ionic block copolymers of alkylene diamines and one or more alkylene oxides; non-ionic acetylenic glycols and reaction products thereof with alkylene oxides; non-ionic polyethylene glycol esters; non-ionic polyoxyethylene ethers of oleyl alcohol; anionic phosphate esters of an ethoxylated alkylphenol, potassium salt; non-ionic block copolymers prepared by the sequential addition of ethylene oxide and then propylene oxide to an ethylene glycol base; non-ionic block copolymers prepared by sequential addition of propylene oxide and then ethylene oxide to a propylene glycol nucleus wherein (a) the molecular weight of the resulting poly (oxypropylene) portion of the copolymer ranges from about 1750 to about 2750 and the resulting percent poly (oxyethylene) portion in the total copolymer molecular is from about 10 to about 30, (b) said molecular weight is from about 2750 to about 4000 and said percent poly(oxyethylene) is from about 10 to about 20, (c) said molecular weight is 950 and said percent poly (oxyethylene) is 10, (d) said molecular weight is 1200 and said percent poly (oxyethylene) is 20; and mixtures of such.
 31. The composition of claim 30 wherein said set accelerating agent is a calcium chloride.
 32. The composition of claim 30 wherein said compound (b) is present in an amount of from about 1 to about 25 percent by weight of the total additive composition.
 33. The composition of claim 30 additionally containing a small amount of the condensation product of octylphenol with sufficient ethylene oxide to give in excess of 50 percent poly (oxyethylene) in the total molecule, said amount of said additional product being sufficient to render said component (c) more soluble in water and thereby prevent such component from separating out from said said additive composition. 